In a natural forest of British Columbia, paper birch and Douglas fir grow together in early successional forest communities. They compete with each other, but our work shows that they also cooperate with each other by sending nutrients and carbon back and forth through their mycorrhizal networks.

e360: And they can tell when one needs some extra help versus the other, is that correct?

Simard: Thatís right. Weíve done a bunch of experiments trying to figure out what drives the exchange. Keep in mind that itís a back and forth exchange, so sometimes the birch will get more and sometimes the fir will get more. It depends on the ecological factors that are going on at the time.